Hemostatic Powder Delivery Devices and Methods

ABSTRACT

The present invention is directed to a device for the expression of a hemostatic powder having an elongated reservoir with a manual air pump, such as a bellows, at a proximal end and an expression port at a distal end. A porous filter is slidably disposed within the reservoir between the bellows and plunger and the expression port, and a spring is disposed within the reservoir between the air pump and the plunger. The powder is disposed within the reservoir between the porous filter and the expression port, and the pump is in a fluid communication with the expression port through the porous filter and through the powder.

FIELD OF THE INVENTION

The present invention is directed to Hemostatic Powder Delivery Devicesand Methods, particularly to hand-operated devices which can be operatedwith one hand to express topical absorbable hemostatic powders directlyonto a wound.

BACKGROUND OF THE INVENTION

In a wide variety of circumstances, animals, including humans, cansuffer from bleeding due to wounds or during surgical procedures. Insome circumstances, the bleeding is relatively minor, and normal bloodclotting functions in addition to the application of simple first aidare all that is required. In other circumstances substantial bleedingcan occur. These situations usually require specialized equipment andmaterials as well as personnel trained to administer appropriate aid.

In an effort to address the above-described problems, materials havebeen developed for controlling excessive bleeding. Topical AbsorbableHemostats (TAHs) are widely used in surgical applications. TAHsencompass products based on oxidized cellulose (OC), oxidizedregenerated cellulose (ORC), gelatin, collagen, chitin, chitosan, etc.To improve the hemostatic performance, scaffolds based on the abovematerials can be combined with biologically-derived clotting factors,such as thrombin and fibrinogen.

The control of bleeding is essential and critical in surgical proceduresto minimize blood loss, to reduce post-surgical complications, and toshorten the duration of the surgery in the operating room. Due to itsbiodegradability and its bactericidal and hemostatic properties,oxidized cellulose, as well as oxidized regenerated cellulose has longbeen used as a topical hemostatic wound dressing in a variety ofsurgical procedures, including neurosurgery, abdominal surgery,cardiovascular surgery, thoracic surgery, head and neck surgery, pelvicsurgery and skin and subcutaneous tissue procedures. A number of methodsfor forming various types of hemostats based on oxidized cellulosematerials are known, whether made in powder, woven, non-woven, knit, andother forms. Currently utilized hemostatic wound dressings includeknitted or non-woven fabrics comprising oxidized regenerated cellulose(ORC), which is oxidized cellulose with increased homogeneity of thecellulose fiber. Examples of such hemostatic wound dressingscommercially available include SURGICEL SNoW® Absorbable Hemostat;SURGICEL® Original Absorbable Hemostat; SURGICEL® FIBRILLAR™ AbsorbableHemostat; SURGICEL NU-KNIT® Absorbable Hemostat; all available fromJohnson & Johnson Wound Management Worldwide, a division of Ethicon,Inc., Somerville, N.J., a Johnson & Johnson Company. Other examples ofcommercial resorbable hemostats containing oxidized cellulose includeGelitaCel™ resorbable cellulose surgical dressing from Gelita MedicalBV, Amsterdam, The Netherlands. The commercially available oxidizedcellulose hemostats noted above are knitted or nonwoven fabrics having aporous structure for providing hemostasis.

Hemostatic materials can also be provided in powdered form, such as forexample powders based on purified plant starch, clay, zeolite granules,fibrinogen, thrombin, mixtures of fibrinogen and thrombin, etc. There isa need in delivering these and similar hemostatic materials in a powderform to the surface of tissue or wound for controlling bleeding.

The existing devices for delivering hemostatic powders lack uniformityin delivery, with quantity of powder delivered at the beginning ofexpression varying from quantity of powder delivered at the end of theexpression. Also the existing device have significant variability inpowder delivery under varying angles of spray, i.e. when orientation ischanging from horizontal to vertical and any angle in-between. Further,the existing devices might not perform well in laparoscopic deliverymodes, may clog, or may express some powder prior to actuation, i.e. dueto powder leakage from the devices.

U.S. Pat. No. 6,866,039 discloses a dispensing apparatus for dispensinga powdered product comprising: a housing defining an outlet, a shafthaving a storage chamber therein for a powdered product provided with afirst inlet and a first outlet, a sheathing member slidably mounted onthe shaft and having a second inlet and a second outlet closed by afrangible membrane, and a variable volume member operatively connectedto the shaft; wherein the shaft is moveable, on operation of thevariable volume member to reduce the variable volume so as to pressurizegas in an interior of the variable volume member, from an initialstorage position in which the first and second inlets are out ofalignment so as to close a gas flow path, to a dispensing position, inwhich the first and second inlets are brought into alignment by actionof the housing against the sheathing member and in which the frangiblemembrane is ruptured by the shaft so as to open the gas flow path, suchthat pressurized gas from the interior of the variable volume member isdischarged along the gas flow path comprising the first and secondinlets, storage chamber, second outlet and first outlet, to therebyentrain powdered product and dispense it through the housing outlet.

U.S. Pat. No. 8,056,762 discloses a hand-held dispenser for dispensing apharmaceutical product, the dispenser comprising: a housing providing aduct; a frangible membrane provided in the duct; a probe with a piercingtip mounted in the duct, the probe being arranged such that, in use, thepiercing tip pierces the frangible membrane; an air compression deviceto compress air for expelling a pharmaceutical product through theprobe; and a channel to substantially equalize the pressure in the aircompression device and the pressure above the frangible membrane,wherein the frangible membrane is provided on a sheath which comprises afirst larger diameter portion and a second axially spaced smallerdiameter portion defining an external shoulder therebetween, and theinside surface of the duct has a corresponding internal shoulder to beengaged by the external shoulder of the sheath and an axial spacer isprovided on one or both of the external and internal shoulders tomaintain the channel past the engaged shoulders.

Published U.S. Patent Application 2012/0103332 discloses a powderdelivery device, comprising: a body; a nasal adapter; a piercing devicebetween the nasal adapter and the body; a blister between the piercingdevice and the body, wherein the blister contains a powder; a bellows; aspring; and an actuator.

U.S. Pat. No. 7,923,031 discloses a powder delivery system comprising: achamber storing a hemostatic composition comprising dry gelatin powderhaving a mean particle size in the range of 30-250 micrometers andhyaluronic acid, said chamber having at least one discharge openingsized for distributing said composition.

European Publication No. 1,322,356 discloses a device for deliveringmultiple doses of physiologically active agent in powdered form, thedevice comprising: a manually rechargeable air reservoir; a powdercontainer defining therein a plurality of individual receptacles, eachreceptacle containing a discrete metered dose of powder, a powderdelivery passage for the forced flow therethrough to a patient of airwith a said metered dose of powder entrained therein so as substantiallyto empty a said receptacle, a closure for restricting the unwantedingress of moisture into the device via said passage when the device isnot in use; and a container indexing mechanism for indexing movement ofsaid container to move a substantially empty said receptacle out ofcommunication with said powder delivery passage and to move a freshpowder-containing said receptacle into communication with said powderdelivery passage; wherein the device is constructed and arranged so thatthe action of opening or closing said closure (i) operates saidcontainer indexing mechanism and (ii) charges the air reservoir withair.

European Publication No. 2,042,208 discloses a dispensing device fordispensing a formulation as a spray, wherein the dispensing device isadapted to receive or comprises a storage device with at least one ormultiple, preferably separate and pre-metered doses of the formulation,wherein the dispensing device comprises a means for pressurizing gas, inparticular air, or an air inlet for generating or allowing a gas streamflowing through the storage device for dispensing a dose of theformulation, characterized in that the dispensing device is designedsuch that pressure pulses are generated in the gas stream duringdispensing one dose and/or the direction of gas flow alternates duringdispensing one dose.

U.S. Pat. No. 7,540,282 discloses an inhaler, comprising: a sealedreservoir including a dispensing port; a linear channel communicatingwith the dispensing port and including a pressure relief port; a conduitproviding fluid communication between an interior of the sealedreservoir and the pressure relief port of the channel; a cup assemblymovably received in the channel and including, a recess adapted toreceive medicament from the reservoir when aligned with the dispensingport, a first sealing surface adapted to seal the dispensing port whenthe recess is not aligned with the dispensing port, and a second sealingsurface adapted to seal the pressure relief port when the recess isaligned with the dispensing port and to unseal the pressure relief portwhen the recess is not aligned with the dispensing port.

Chinese Patent publication No. 203263962 discloses a utility model thatrelates to a hemostatic dry powder spraying bottle. The hemostatic drypowder spraying bottle comprises a bottle body made of medical plastic,an inner spraying pipe made of medical plastic, an outer sleeve cap anda handle made of medical plastic, wherein a groove which allows thebottle body to stretch in the axial direction of the bottle body isformed in the outer surface of the bottle body, the inner spraying pipeis arranged on the top of the bottle body in a screwed mode throughthreads, the inner spraying pipe is sleeved with the outer sleeve cap,the lower end of the outer sleeve cap is connected with the bottle body,and the handle is fixedly connected with the bottle body. The hemostaticdry powder spraying bottle is simple and novel in structure, low incost, convenient to use, even in exerted force, complete in powderspraying and good in powder spraying effect and hemostatic effect.

There is a need in improved delivery devices for delivering hemostaticpowders to the surface of tissue or wound for controlling bleeding.

SUMMARY OF THE INVENTION

The present invention relates to a device for expression of a powder,comprising: an elongated hollow reservoir, the reservoir having a manualair pump attached to the reservoir, the reservoir having an expressionport at a distal end of said reservoir, a porous filter slidablydisposed within the reservoir between said air pump and said expressionport; a spring disposed within the reservoir between the air pump andthe filter; wherein the powder is disposed within the reservoir betweenthe filter and the expression port, and wherein the pump is in a fluidcommunication with the expression port through the porous filter andthrough the powder.

BRIEF DESCRIPTION OF FIGURES

FIG. 1 shows an embodiment of the powder delivery device of the presentinvention in closed configuration.

FIG. 2 shows an embodiment of the powder delivery device of the presentinvention in open configuration.

FIG. 3 shows an embodiment of the powder delivery device of the presentinvention in closed configuration.

FIG. 4 shows an embodiment of the powder delivery device of the presentinvention in open configuration.

FIG. 5 shows an embodiment of the powder delivery device of the presentinvention in an exploded view.

FIG. 6 shows an embodiment of the powder delivery device of the presentinvention in an exploded view.

FIG. 7 shows an embodiment of the powder delivery device of the presentinvention in a partially disassembled view.

FIG. 8 shows an embodiment of the powder delivery device of the presentinvention in a cross-sectional view.

FIG. 9 shows an embodiment of the powder delivery device of the presentinvention in a cross-sectional view.

FIG. 10 shows an embodiment of the powder delivery device of the presentinvention in a cross-sectional view.

FIG. 11 shows an embodiment of the powder delivery device of the presentinvention in a cross-sectional view.

FIG. 12 shows an embodiment of the powder delivery device of the presentinvention in a cross-sectional view.

FIG. 13 shows an embodiment of the powder delivery device of the presentinvention.

FIG. 14 shows an embodiment of the powder delivery device of the presentinvention.

FIG. 15 shows an embodiment of the powder delivery device of the presentinvention in a cross-sectional view.

FIG. 16 shows an alternative embodiment of the powder delivery device ofthe present invention in a cross-sectional view.

FIG. 17 shows an embodiment of the powder delivery device of the presentinvention with elongated cannula attached.

FIG. 18 shows rigid shaft with a shroud.

FIG. 19 shows elongated cannula partially inserted into the rigid shaftwith a shroud.

FIG. 20 shows an embodiment of the powder delivery device of the presentinvention with elongated cannula and rigid shaft with a shroud attached.

FIG. 21 shows an alternative embodiment of the powder delivery device ofthe present invention.

FIG. 22 shows an alternative embodiment of the powder delivery device ofthe present invention.

FIG. 23 shows a schematic rendering of an alternative embodiment of thepowder delivery device of the present invention.

FIG. 24 shows a schematic rendering of a comparative device used intesting.

FIG. 25 shows a chart of the quantities of powder expressed from thecomparative device with each expression or powder burst plotted ascumulative grams expressed relative to the sequential number ofexpression, using vertical orientation of the comparative device.

FIG. 26 shows a chart of the quantities of powder expressed from thecomparative device with each expression or powder burst plotted ascumulative grams expressed relative to the sequential number ofexpression, using horizontal orientation of the comparative device.

FIG. 27 shows a chart of the quantities of powder expressed from thedevice of the present invention plotted as cumulative grams expressedrelative to the sequential number of expressions, using verticalorientation of the inventive device.

FIG. 28 shows a chart of the quantities of powder expressed from thedevice of the present invention plotted as cumulative grams expressedrelative to the sequential number of expressions, using horizontalorientation of the inventive device.

DETAILED DESCRIPTION

Embodiments of the powder delivery device 10 of the present inventionare shown in FIGS. 1-4 in prospective view, FIGS. 5-7 in an explodedview, FIGS. 8-12 in a cross-sectional view, FIGS. 13-14 in a partialprospective internal view. Device 10 comprises a hollow tubular body orreservoir 20 on which a manual air pump, such as a compressible elasticbulb (not shown) or bellows 30 (as shown) is mounted at a proximate end11. Reservoir 20 has an optional hand grip 25 at proximate end 11.Within reservoir 20 is positioned a plunger 40 with an optional filter50 mounted on plunger 40. Plunger 40 with filter 50 is mounted slidablywithin reservoir 20 and is capable of advancing within reservoir 20towards distal end 12. At distal end 12 of reservoir 20 is positioned anopen-ended port 60 which is in fluid communication with reservoir 20.Onto port 60 is axially mounted an optional powder trap 70 onto which isaxially mounted a hub 80, which is integrated with a tubular expressioncannula 90 having a cannula exit 95. Optional O-rings can be provided(not shown) for air-tight mounting of powder trap 70 and hub 80.

Plunger 40 has an optional plunger stem 42 axially extending fromplunger 40 rearward towards proximal end 11. On plunger stem 42 ispositioned spring 45. Spring 45 is positioned between bellows 30 andplunger 40 and partially inside bellows 30, more specifically betweentop of bellows 32 and plunger 40. Plunger 40 and filter 50 are coaxiallyand slidably moveable within reservoir 20. Plunger 40 forms an optionalgap 41 between reservoir 20 and plunger 40, with gap 41 ranging fromabout 0.01 mm to about 2 mm, such as 0.1 mm, 0.2 mm, 0.3 mm or 0.5 mm.Alternatively to optional gap 41, or in addition to a narrow gap 41, atleast one aperture in plunger 40 (aperture not shown) provides for apath for gas to pass from proximal side of plunger 40 to distal side ofplunger 40.

Microporous filter 50 snugly and slidably fits within reservoir 20 andmoves together with plunger 40 onto which filter 50 is mounted. Aportion of reservoir 20 between filter 50 and port 60 is a powdercompartment 22, filled with hemostatic powder (not shown). Volume ofpowder compartment 22 is changing depending on the position of plunger40 and filter 50, and as plunger 40 advances towards distal end 12 ortowards port 60, volume of powder compartment 22 decreases.

As shown in FIGS. 5, 6, 8-10, 12-14, optional powder trap 70 is mountedonto port 60 by any known means, such as by snap-on mounting. Optionalpowder trap 70 provides for a tortuous path for the powder and gasexiting powder compartment 22. Powder trap is formed by trap lid 76covering tortuous path 72 which is a channel having several bends andstarting with an orifice 73 located within powder compartment 22. Asfurther shown in FIGS. 9, 12 tortuous path 72 results in turning of thedirection along which air and powder are advancing within device 10,particularly turning from going generally from proximal towards distaldirection, i.e. from powder compartment 22 to cannula exit 95, to goinga short distance in other direction, such as in sideways directionand/or in opposite direction, i.e. perpendicular to main axis of device10 or rearwards, from distal end 12 towards proximal end 11. This changein the direction along which air and powder advancing within device 10along tortuous path 72 is shown schematically by arrows 100 whichindicate air and powder advancement from proximal end 11 towards distalend 12, with a brief intermittent change in the direction when advancingthrough tortuous path 72.

Powder trap 70 prevents hemostatic powder (not shown) in powdercompartment 22 from exiting device 10 via cannula 90 when no air flow ispresent, i.e. prevents loss of powder especially when device 10 ispositioned with cannula exit 95 points generally downwards, especiallywhen device 10 is subject to shaking or vibration or any variableacceleration movements. Powder trap 70 prevents unintentional expressionof small quantities of powder from powder compartment 22, while allowingpowder expression when driven by air flow.

Optional reservoir ridges 24 and powder trap ridges 75 are graspingfeatures located on the outside surface of reservoir 20 and powder trap70 and enable an optional blocking feature of device 10, providing forblocking orifices 73 serving as entrance to tortuous path 72. Usingpowder trap ridges 75 powder trap can be rotated about reservoir 20 towhich powder trap 70 is snapfit and rotatably attached at port 60. Inthe embodiments of FIGS. 2, 4, 7, 9, 10, 12, 13, when reservoir ridges24 and powder trap ridges 75 are aligned, orifice 73 is open into powdercompartment 22 and not blocked by blocking member 28 within reservoir 20(FIG. 13) so that powder and air can enter tortuous path 72 and exitdevice 10 via cannula exit 95.

In the embodiments of FIGS. 1, 3, 8, 14, when reservoir ridges 24 andpowder trap ridges 75 are not aligned or are rotated at 90° to eachother, orifice 73 is blocked by blocking member 28 within reservoir 20(FIG. 14) and thus orifice 73 is closed preventing powder and airentering tortuous path 72 from powder compartment 22 and exiting device10 via cannula exit 95. This optional blocking feature preventsinadvertent activation of device 10 and inadvertent expression ofpowder.

Referring to FIGS. 9, 11, 12, the flow of air and/or air with entrainedpowder from powder compartment 22 is schematically indicated by arrows100. Bellows 30 is in fluid communication with cannula exit 95 throughgap 41, filter 50, powder compartment 22, tortuous path 72, hub 80, andcannula 90. Upon compression of bellows 30 air moves from bellows 30 viagap 41 and through filter 50 into powder compartment 22. From powdercompartment 22, as also is schematically indicated by arrows 100, powderand air stream are entering tortuous path 72 through orifice 73 and thenmove from tortuous path 72 into hub 80, cannula 90, exiting device 10via cannula exit 95.

Further referring to FIG. 15, which shows schematically a partialcross-sectional view of device 10, as shown in FIG. 15A, upon applyingpressure in the direction schematically shown by arrow 33 on bellows top32, bellows 30 compresses generating air pressure inside bellows 30. Airis then moving through device 10 as schematically indicated by arrows100 from bellows 30 via gap 41 and through filter 50 into powdercompartment 22. From powder compartment 22, powder 110 and air streamare expressed from the device via cannula 90 (not shown in FIG. 15).

Upon release of pressure on bellows 30, bellows 30 returns touncompressed state, creating a vacuum inside bellows 30. Air or gas isinspired into bellows 30, with air entering device 10 via cannula 90,passing through powder compartment 22, and filter 50. Filter 50 preventspowder penetration into bellows 30 so that bellows 30 is substantiallyfree of powder throughout the expression.

Powder compartment 22 is maintained so that the volume of powdercompartment 22 is substantially filled with powder, with substantiallyno free air space or minimal free air space. The inventors surprisinglydiscovered that such arrangement results in better uniformity of powderexpression throughout the expression cycle, i.e. from when device 10 isfully charged with powder to emptying of powder compartment 22 of allremaining powder, as well as in better directional expressinguniformity, i.e. in minimal differences between the expression of powderwith cannula 90 directed horizontally relative to directed vertically.Powder compartment is also maintained under low compression or nocompression. The inventors surprisingly discovered that such arrangementresults in much better uniformity of powder expression and preventsaggregation and agglomeration of powder.

Spring 45 serves as a compressible advancer of plunger 40 and filter 50.As bellows 30 is depressed, bellows 30 generates flow of air expressingpowder from device 10. Simultaneously, top of bellows 32 is compressingspring 45, which in turn applies pressure on plunger 40 and filter 50causing plunger 40 and filter 50 to move in distal direction, decreasingthe volume of powder compartment 22 as powder is expressed from device10.

Thus with each depression of bellows 30 generating air flow and powderexpression from powder compartment 22, plunger 40 with filter 50 aresimultaneously driven towards distal end 12 by spring 40 which isdepressed upon compression of bellows 30. Thus upon each expression ofpowder from device 10, plunger 40 with filter 50, advances distally totake up the space freed by expressed powder. This action results involume of powder compartment 22 being constantly adjusted to correspondto the volume of powder remaining in powder compartment 22.

Advantageously, upon release of bellows 30 pressure on spring 45 isreleased and spring can expand rearward or proximally freely, withoutpulling on plunger 40 with filter 50. Advantageously, spring 40 is notattached to bellows 30, resulting in spring 40 not being pulledproximally upon release of pressure on bellows 30 and expansion ofbellows 30 into uncompressed state. Advantageously, plunger 40 withfilter 50 are snugly and slidably fit inside reservoir 20 and remain inposition furthest advanced during powder expression. During theinspiration of air into bellows, when pressure on bellows 30 is removedallowing bellows to expand, plunger 40 with filter 50 are not moving inproximal direction, instead maintaining the closest position to distalend 12 achieved during the prior powder expression cycle. The frictionalengagement of plunger 40 with filter 50 against reservoir 20 preventseasy movement of plunger 40 with filter 50 rearward, i.e. in proximaldirection.

Depression of bellows 30 results in simultaneous generation of gaspressure within device 10 and pressure on spring 45 which in turn forcesplunger 40 with filter 50 advance within powder compartment 22 to takeup any space freed by powder 110 expressed from powder compartment 22.

Advantageously, prior to any expression, there is no or very littlepressure on powder in powder compartment 22. Because there is no or verylittle constant pressure of spring 45 on powder in powder compartment22, potential agglomeration and caking of powder are prevented.

Referring to FIG. 15A, spring 45 is shown positioned on plunger stem 42.Spring 45 is situated between top of bellows 32 and plunger 40, and isshown touching top of bellows 32. Alternatively, as shown in FIG. 15B,spring 45 can end at a distance 46 from top of bellows 32, distance 46ranging from 0 mm to about 20 mm, such as 3 mm, 5 mm, 7 mm, 15 mm. FIG.15B can represent an initial position of spring 45, prior to anyexpression of powder 110.

FIG. 15B also shows position of spring 45, plunger 40 with filter 50,and powder compartment 22 after one or more powder 110 expressions. Asshown in FIG. 15B, upon expression of powder 110 from powder compartment22, volume of powder compartment 22 decreases with plunger 40 withfilter 50 advancing within reservoir 20 and taking freed space. Asshown, spring 45 is positioned at distance 46 from top of bellows 32,with distance 46 increasing after each expression.

Referring to FIGS. 16A and 16B, an alternative embodiment of the presentinvention is shown, in a view similar to the view shown in FIGS. 15A and15B, whereby spring 45 and optionally plunger 40 are made ofcompressible foam.

Cannula 90 shown in FIGS. 1-9 is a tubular powder expression member,made of polymer or metal, and can be flexible, semi-flexible, bendable,or rigid. Cannula can have any cross-section, but is preferably tubularwith internal diameter from 1 mm to 10 mm, such as 2 mm, 3 mm, 4 mm, 5mm. Cannula 90 is preferably flexible and can have the length from 3 cmto about 50 cm, such as 4 cm, 5 cm, 10 cm, 20 cm, 30 cm, 40 cm.

Referring to FIG. 17, an elongated cannula 92 useful for laparoscopicapplications is shown attached to device 10 at hub 80.

Referring to FIG. 18, a hollow tubular rigid shaft 94 attached to shroud82 is shown. Rigid shaft 94 is utilized to be positioned over elongatedcannula 92 to maintain elongated cannula 92 in a straight linearconfiguration for delivery through laparoscopic ports and trocars. Rigidshaft 94 has internal diameter closely matching or slightly larger thanexternal diameter of elongated cannula 92, for easy insertion ofelongated cannula 92 into rigid shaft 94. FIG. 19 shows insertion ofelongated cannula 92 with hub 80 into rigid shaft 94 attached to shroud82. Shroud 82 is attachable (such as by snap-on means) onto hub 80and/or onto powder trap 70 and/or onto reservoir 20. FIG. 20 showsdevice 10 with shroud 82 and rigid shaft 94 attached, with elongatedcannula 92 installed and visibly protruding from rigid shaft 94. Thelength of elongated cannula 92 is selected so as to extend from about 0mm to about 30 mm from rigid shaft 94, such as extend by 1 mm, 5 mm, 20mm.

In operation, device 10 filled with powder is brought into a sterilefield in operating room. Device 10, if equipped with blocking feature,is then unblocked by aligning reservoir ridges 24 and powder trap ridges75. Prior to unblocking, or after unblocking, device is directed at thewound or tissue that requires application of hemostatic powder,optionally through a laparoscopic port. Bellows 30 is then depressed,releasing a first portion of hemostatic powder. Bellows 30 is thenreleased, allowing inspiration of air into bellows 30. Steps ofdepressing and releasing of bellows 30 are then continued sequentiallyas needed, expressing hemostatic powder towards tissue as needed.

In the device operation, there a number of ways a health practitionercan hold the device for delivering the hemostatic powder. In oneapplication technique, the device 10 is held with one hand, grippingreservoir 20 between index finder and middle finger, or between middlefinger and ring finger, and pressing on bellows 30 with the thumb of thesame hand for powder expression.

In an alternative application technique, the device 10 is held with onehand, gripping reservoir 20 in a fist by wrapping one or more or indexfinder, middle finger, ring finger, and little finger, and pressing onbellows 30 with the thumb of the same hand for powder expression.Alternatively, device 10 can be held as convenient by one hand anywhereon reservoir 20, and the bellows 30 can be depressed by another hand.Many other convenient techniques of holding device 10 and depressingbellows 30 for expression of hemostatic powder are possible.

FIG. 21 shows an embodiment of device 10 whereby spring 45 is mountedonto plunger stem 42 between plunger 40 and flange 49. Spring 45 isunder constant compression and constantly exerts pressure onto plunger40. As shown in FIGS. 21A and 21B, upon depressing bellows 30, air movesthrough the device in a similar way as described above, resulting inexpression of powder 110 from powder compartment 22. Pressure fromspring 45 forces plunger 40 with filter 50 advances within powdercompartment 22 to take up any space freed by powder 110 expressed frompowder compartment 22.

FIG. 21B shows position of spring 45, plunger 40 with filter 50, andpowder compartment 22 after one or more powder 110 expressions. Uponexpression of powder 110 from powder compartment 22, volume of powdercompartment 22 decreases with plunger 40 with filter 50 advancing withinreservoir 20 and taking freed space. As shown, spring 45 has expandedand takes all space between flange 49 and plunger 40.

FIG. 22 shows an alternative embodiment of the present invention, in aview similar to the view shown in FIGS. 21A and 21B, whereby spring 45and optionally plunger 40 are made of compressible foam.

FIG. 23 shows an embodiment of inventive device 16 having, no optionalpowder trap 70, no optional tortuous path 72, no optional orifice 73; nooptional reservoir ridges 24 and powder trap ridges 75; no optionalblocking feature providing for blocking orifice 73; no optional blockingmember 28. Device 16 operates in a similar way to embodiments shown inFIGS. 1-20, whereby upon depressing bellows 30, air moves through thedevice in a similar way as described above, resulting in expression ofpowder 110 from powder compartment 22. Pressure from spring 45 forcesplunger 40 with filter 50 to advance within powder compartment 22 totake up any space freed by powder 110 expressed from powder compartment22.

Reservoir 20 can be of any cross-sectional shape, such as rectangular oroval, and is preferably of circular cross-sectional shape, with internalcross-sectional diameter ranging from about 8 mm to about 40 mm, such as10 mm, 15 mm, 20 mm, 21 mm, 25 mm, and 30 mm.

Bellows 30 has generally a tubular shape and is made of resilientpolymeric material, such as polyethylene or polypropylene that enablesbellows 30 to be compressed by applying pressure on top of bellows 32,so that when the pressure is removed bellows 30 returns to substantiallythe same shape as before the compression was applied. Bellows 30 iscompressible from about 2:1 ratio of initial height to compressed heightto about 6:1 ratio, such as 3:1 ratio of initial height to compressedheight. In one embodiment, bellows 30 is about 22 mm in diameter, about30 mm in uncompressed state, and about 10 mm in fully compressed state,having from 3 to 10 hinges, such as 5 hinges as shown in FIG. 1.

Microporous filter 50 can be made of any porous media such asmicro-porated or sintered polymeric material, e.g. PTFE, polyethylene,polypropylene, or similar, preferably with interconnected pores orchannels to selectively allow gas flow through filter 50 whilepreventing flow of powder through filter 50. Pore size or channeldensity are selected to selectively block passage of powder particlesbeing used, for instance particles ranging from 0.001 mm to 1.0 mm insize, more preferably from 0.05 mm to 0.5 mm, such as particles witheffective diameter of 0.05 mm, 0.1 mm, 0.15 mm, 0.20 mm, 0.25 mm, 0.3mm, 0.35 mm, 0.5 mm. In one embodiment, pore size is at least 20% lowerthan the average size of particles of the hemostatic powder, such as 50%lower. In the preferred embodiment, filter 50 will block passage ofparticles with size greater than 0.05 mm.

Spring 45 can be any spring of known types, such as metal wire basedspring, or polymeric string based spring. Alternatively, spring 45 ismade of compressible and resilient foam.

Filling device 10 with an appropriate hemostatic powder can be performedin a variety of ways. In one method of filling device 10, device 10 isprepared for filling with bellows 30, plunger 40, filter 50, spring 45removed from reservoir 20, while powder trap 70 is mounted onto port 60,with orifice 73 blocked by blocking member 28 within reservoir 20 andthus closing orifice 73 and preventing powder entering tortuous path 72.Reservoir 20 is then oriented with proximal end 11 facing generallyupwards, and reservoir 20 is filled by hemostatic powder gravimetricallyor volumetrically through open proximal end 11. In one embodiment,device 10 is filled with 2-10 g of hemostatic powder, such as 3 g, 4 g,or 5 g of hemostatic powder by weight. Thereafter, maintaining verticalorientation of device 10 with proximal end 11 facing generally upwards,plunger 40 and filter 50 are inserted into reservoir 20 from proximalend 11. Thereafter spring 45 is mounted onto plunger stem 42 and bellows30 is attached to reservoir 20 at proximal end 11.

Example 1

Powder expression—Comparative

A comparative device that is commercially available as the Arista™delivery device is available from Davol Inc., a subsidiary of C. R.Bard, Inc. The comparative device is pre-filled with 3 g of plant basedabsorbable surgical hemostatic powder derived from purified plantstarch, with no modifications made to the commercially availablecomparative device or powder filling of said device. The comparativedevice used in the testing is shown schematically in FIG. 24.Comparative device 17 comprises bellows 30 mounted onto reservoir 20with grip 25. Powder compartment 22 within reservoir 20 is pre-filledwith the hemostatic powder. Device 13 had a tubular expression cannula90 having a cannula exit 95.

Referring to FIGS. 25 and 26, the results of powder expression testingusing comparative device 17 are shown of FIG. 24. The powder wasexpressed in sequential expressions or bursts when the comparativedevice was oriented vertically (with cannula 90 and cannula exit 95facing downwards) with the data presented in FIG. 25; or horizontally(with cannula 90 and cannula exit 95 facing horizontally) with the datapresented in FIG. 26. The quantities of powder expressed with eachexpression or powder burst were measured and plotted as cumulative gramsexpressed vs. the sequential number of expression. As can be seen fromFIG. 25, the comparative device shows highly non-uniform expression ofhemostatic powder in vertical orientation, whereby only two expressionsexpress almost all of the powder, and by the fourth expression all 3 gof powder are expressed. This expression pattern is highly non-uniformand inconvenient for the health practitioner, overloading first andsecond expressions and then expressing little or no powder. Thisexpression pattern is also inconvenient for covering areas of tissue orwound as in only two expressions 80% of the hemostatic powder isexpressed leaving nothing for adjacent areas of tissue. Overall in fourexpressions, all 3 grams of powder were expressed, i.e. on average about0.75 g per expression was expressed, with first two expressionsdelivering on average about 1.25 g per expression.

As can be seen from FIG. 26, the comparative device shows non-uniformand incomplete expression of hemostatic powder also in horizontalorientation, whereby by seventh expression of powder the expression ofpowder ceases with only 2 g or 66% of powder expressed, and 33% ofpowder still remaining in the device. This expression pattern isinconvenient for the health practitioner, whereby the remaining powderceases to be expressed from the device in horizontal orientation. Onaverage, the device expressed about 0.25 g per expression, but alsofailed to express all powder.

Further, with health practitioner changing the direction of expressionfrom horizontal to vertical or any angle in-between, the expressionpatterns will also change, resulting in unpredictable patterns andexpressing more or less powder than expected or needed in eachexpression. For instance, as shown above, changing orientation canresult in changes from 1.25 g per expression to 0.25 g per expression.

Example 2

Powder Expression

The hemostatic powder used in testing of the devices of presentinvention was made from oxidized regenerated cellulose by milling androller compaction. Briefly, SURGICEL' ORC fabric was subject to millingand roller compaction. The resulting powder target size was 75 μm -300μm.

Referring to FIGS. 27 and 28, the results of powder expression testingin the inventive device are shown. Device 10 was loaded with 3 g ofhemostatic ORC powder as described above, and the powder was expressedin sequential expressions or powder bursts when device 10 was orientedvertically (with cannula 90 and cannula exit 95 facing downwards), withthe data presented in FIG. 27; or horizontally (with cannula 90 andcannula exit 95 facing horizontally), with the data presented in FIG.28). The quantities of powder expressed with each 5 expressions orpowder bursts were measured and plotted as cumulative grams expressedvs. the number of expression. As can be seen from FIG. 27, device 10shows highly uniform expression of hemostatic powder in verticalorientation, whereby all 3 g of hemostatic powder are expressed in about35 uniform expressions (grouped in FIG. 27 by five expressions). Thisexpression pattern is uniform and convenient for the healthpractitioner, resulting in predictable hemostatic powder delivery anddelivering smaller quantities of powder, i.e. about 0.075-0.10 g ofpowder per expression, such as 0.085 g of powder per expression.

As can be seen from FIG. 28, device 10 shows highly uniform expressionof hemostatic powder in horizontal orientation as well, whereby all 3 gof hemostatic powder are expressed in seven uniform expressions, albeitwith the seventh expression being somewhat lower than previous six. Thisexpression pattern, similarly to data in FIG. 27, is uniform andconvenient for the health practitioner, resulting in a predictablehemostatic powder delivery and delivering smaller quantities of powder,i.e. about 0.075-0.10 g of powder per expression, such as 0.085 g ofpowder per expression.

Further, with health practitioner changing the direction of expressionfrom horizontal to vertical or any angle in-between, the expressionpatterns will remain substantially unchanged, resulting in predictablepatterns and expressing approximately same amount of powder in eachexpression independently of the orientation of device 10. Device 10demonstrates substantial independence of the expression of powder fromorientation, with orientation changing from downward vertical tohorizontal. Further, device 10 demonstrates per expression quantities atthe beginning of the powder delivery, i.e. when device 10 is 90-100%full with powder, very similar to per expression quantities at the endof the powder delivery, i.e. when device 10 is almost emptied of thepowder, or has 5% -15% powder remaining. Per expression quantities atthe beginning of the powder delivery are preferably varying by not morethan 5% to 25%, such as varying by not more than 5%, 10%, or 20%.

Having shown and described various versions in the present disclosure,further adaptations of the methods and systems described herein may beaccomplished by appropriate modifications by one of ordinary skill inthe art without departing from the scope of the present invention.Several of such potential modifications have been mentioned, and otherswill be apparent to those skilled in the art. The scope of the presentinvention should be considered in terms of the following claims and isunderstood not to be limited to the details of structure and operationshown and described in the specification and drawings.

I/We claim:
 1. A device for expression of a powder, comprising: a) anelongated hollow reservoir, the reservoir having a manual air pumpattached to the reservoir and an expression port at a distal end of saidreservoir, b) a porous filter slidably disposed within the reservoirbetween said air pump and said expression port; c) a spring disposedwithin the reservoir between the air pump and the filter; wherein thepowder is disposed within the reservoir between the filter and theexpression port, and the pump is in a fluid communication with theexpression port through the porous filter and through the powder.
 2. Thedevice of claim 1, wherein said manual air pump comprises a bellows. 3.The device of claim 1, wherein said filter comprises interconnectedpores or channels having size substantially preventing the powder frompassing through the filter.
 4. The device of claim 1, wherein saidporous filter is attached to a plunger slidably disposed within thereservoir between said filter and said manual air pump and a hollowexpression cannula is attached to said expression port and extends fromthe device distally, said expression cannula is in fluid communicationwith said pump.
 5. The device of claim 4, wherein said plunger has anelongated stem extending from said plunger towards the proximal end andsaid spring is at least partially supported on said stem.
 6. The deviceof claim 4, further comprising a) a powder trap positioned between theexpression port and the expression cannula, the powder trap comprisingi) a tortuous channel for the powder, the channel having an entranceorifice open to the reservoir and an exit opening open to the expressioncannula.
 7. The device of claim 6, further comprising a blocking memberwithin the reservoir, wherein said powder trap is rotatable about thereservoir from a first position to a second position and in the firstposition the entrance orifice is blocked by the blocking member and inthe second position the entrance orifice is not blocked by the blockingmember.
 8. The device of claim 6, wherein the pump is in the fluidcommunication with the expression cannula through the reservoir, theplunger, the porous filter, the powder, the entrance orifice, thetortuous channel, and the exit opening.
 9. The device of claim 6,further comprising a gap between the plunger and a wall of thereservoir.
 10. The device of claim 6, wherein the plunger has at leastone aperture establishing the fluid communication between the air pumpand the porous filter.
 11. The device of claim 6, wherein the spring isin a non-compressed state prior to expressing the powder.
 12. The deviceof claim 6, wherein the spring is compressed towards the distal end bycompressing the air pump.
 13. The device of claim 6, wherein the porousfilter is advancing within the reservoir driven by the spring towardsthe distal end.
 14. The device of claim 1, wherein said powder is ahemostatic powder.
 15. The device of claim 1, wherein said powder is anORC powder.
 16. The device of claim 1, wherein a quantity of the powderexpressed from the device is substantially independent of the deviceorientation.
 17. The device of claim 1, wherein a quantity of the powderexpressed from the device by each individual expression at the beginningof the powder delivery is varying by not more than 10% from the quantityof the powder expressed from the device by each individual expression atthe end of the powder delivery.
 18. The device of claim 1, wherein thespring comprises a resiliently compressible metallic spiral, aresiliently compressible polymeric spiral, or resiliently compressiblefoam.
 19. A method for expressing a hemostatic powder comprising thesteps of: a) directing the expression port of the device of claim 1towards a target; b) compressing the air pump thus supplying apressurized air into the reservoir and simultaneously compressing thespring thus exerting pressure on the filter; c) allowing the pressurizedair to reach the powder through the porous filter and to exit the devicefrom the expression port with a portion of the powder; d) simultaneouslyadvancing the filter towards the distal end under pressure from thespring, thus keeping the powder compressed under the filter; e)releasing the air pump allowing an ambient air to refill the air pump;f) optionally repeating the steps (b) through (e).